Question

An unstable particle at rest breaks up into two fragments
ofunequal mass. The mass of the lighter fragment
is2.40 10-28 kg, and that of the heavier fragmentis
1.66 10-27 kg. If the lighter fragment has
aspeed of 0.893c after the breakup, what is the speed
ofthe heavier fragment?
Your answer differs from the correct answerby 10% to
100%.c